use commas for list of jetty maintainers

Signed-off-by: Lachlan Roberts <[email protected]>

library/jetty

@@ -1,6 +1,6 @@
 Maintainers: Greg Wilkins <[email protected]> (@gregw),
-             Lachlan Roberts <[email protected]> (@lachlan-roberts)
-             Olivier Lamy <[email protected]> (@olamy)
+             Lachlan Roberts <[email protected]> (@lachlan-roberts),
+             Olivier Lamy <[email protected]> (@olamy),
              Joakim Erdfelt <[email protected]> (@joakime)
 GitRepo: https://github.com/eclipse/jetty.docker.git